Global Differential GPS (GDGPS) System Future

Christine Bonniksen NASA Management Office NASA Headquarters Presentation Purpose

• Provide Purpose and Status of NASA initiated GDGPS Working Group • Solicit input from PNT Advisory Board to support data analysis and inform GDGPS Working Group Recommendations Outline

• GDGPS Overview • GDGPS Working Group • Summary and Advice Questions GDGPS Overview Global Differential GPS (GDGPS) System

• Designed to improve upon the positioning and timing accuracy provided by operational GPS • Provides real-time corrections to the GPS broadcast message, enabling global sub-10-centimeter accurate positions • Estimates the precise orbits and clock states of the GPS satellites • Create global differential corrections within seconds • Monitors system stability • Does the same for most current GNSS systems The Global Differential GPS (GDGPS) System

Provides real-time GNSS products – continuously – since 2000 Multi-GNSS constellations: GPS, GLONASS, BeiDou, Galileo, QZSS ~5 cm real-time positioning globally GNSS Monitoring

Real-Time Tracking Network Reliable Redundant Data Centers Precision Industrial (Core is NASA’s network) Positioning

Measurements Products, Services

Personal Geolocation

Time-critical environmental Provides near real-time Repeat pass positioning Prototype system and testbed monitoring services infrastructure for Sentinel-6 support for UAVSAR for next generation GPS (Earthquake monitoring, weather products, including airborne radar Control Segment (OCX) tsunami prediction, etc.) radio-occultation

6 Global Tracking Resources Based on NASA’s Global GNSS Network

• 80+ global tracking sites deployed, controlled, operated and maintained by JPL for NASA • JPL installs and maintains receiver hardware (UNAVCO subcontract) • JPL software edits and streams data every second • Monitoring multiple GNSS: GPS, GLONASS, Galileo, BeiDou and QZSS • Hundreds of additional sites contributed by US and foreign agencies leveraged to increase redundancy and diversity

7 Global Differential GPS (GDGPS) System Core Software

Post-processing Real-time processing

Core GipsyX/RTGx Software

• Data editor Space geodesy • Orbit integrator and force models GDGPS real-time • GNSS signal models operations operations • Geodetic quality Earth models software • Filter (optimized fit forward in time) software • Smoother (optimized fit for all time)

Space geodesy products GDGPS real-time products - Flex Power Monitoring - Satellite Signal Monitoring - Orbit and Clock updates - Signal Editing Global Differential GPS (GDGPS) System Working Group

26-Feb-2019 Update on GDGPS 9 Global Differential GPS (GDGPS) System Working Group Establishment

• NASA and JPL were evaluating the future of GDGPS due to the changing commercial markets, emerging dependencies on the GDGPS products and software, and an increasing user base that was not contributing to maintaining the baseline capability • NASA determined that reviewing individual tasks would not provide the necessary knowledge to identify the NASA and national needs of the this capability • The GDGPS working group was established in May 2020 • Membership: • NASA HQ/SCAN • NASA HQ/Earth Science Division • NASA HQ/NASA Management Office • Jet Propulsion Laboratory Global Differential GPS (GDGPS) System Working Group Purpose

• Establish Capability Baseline necessary for current and future NASA and National needs • Identify Future Operating Construct • Funding source(s) and structure • Government/FFRDC or Commercial • Identify any necessary inter-agency cooperation and methods for codifying the cooperation Global Differential GPS (GDGPS) System Issues

• End users do not recognize GDGPS dependencies due to no direct interface • Funding to maintain capability • Currently provided by users directly requesting unique products • Not all users of the GDGPS products provide funding to support basic capabilities Evaluation of Commercial Precise Point Positioning (PPP) Services (work in progress)

GDGPS Parent Company Provider Service/s Users Coverage1 Ref. Network Dependency Standard Maritime Global GDGPS Ref. Data Veripos (UK) Ultra Maritime Global VERIPOS2 Ind. Backup Apex Maritime Global VERIPOS2 Ind. Backup Hexagon AB (Sweden) TerraStar-X Agriculture Regional3 TERRASTAR4 - TerraStar TerraStar-C PRO Land, UAS Global TERRASTAR4 - (UK) TerraStar-C Land, UAS Global TERRASTAR4 - TerraStar-L Land, UAS Global TERRASTAR4 -

StarFire Subscription Service: 5 Land Only Land Global Starfire Network - NavCom Deere & Co (USA) StarFire Subscription Service: All 5 (Canada) Area Maritime Global Starfire Network - StarFire Over IP All Internet Starfire Network5 - Trimble-RTX Land Global Trimble 6 - Trimble (USA) - VRS Services Land Selected Areas7 Trimble 6 - xFill Premium Land Global Trimble 6 - Fugro8 Fugro- Marinestar Positioning Services Maritime Global (<70°N) Fugro Network Ind. Backup (Netherlands) Marinestar Marinestar Arctic Services9 Maritime Arctic (>70°N) Fugro Network Ind. Backup Atlas Basic All Global ~200 stations11 Divested12 10 Hemisphere 11 12 UniStrong (China) GNSS (USA) Atlas H10 All Global ~200 stations Divested Atlas H30 All Global ~200 stations11 Divested12 Skylark Cloud Corrections 13 11 Swift Navigation (USA) - Service Land, UAS Regional Skylark Network - Selected TopCon GNSS TopCon (Japan) - TopNET Land, UAS Countries Network11 - DLR & Telespazio Spaceopal 15 (Europe) 14 (Germany) NAVCAST All Internet ~100 IGS stations - 13 Uniqueness of Global Differential GPS (GDGPS) System Domestic Providers of Similar Positioning Services

Attribute JPL General Provider Capabilities Constellation: GPS Yes Yes GLONASS Yes Yes BeiDou Yes No Galileo Yes No QZSS Yes No Green indicates Independent of user receiver or Yes No not provided software Global feed (uniformly valid; use Yes No commercially anywhere) No geographical limits Yes Yes Access available: Internet Yes Yes Secure Land Line Yes No Secure VPN Yes No GPS III models Yes No Attitude Quaternions Yes No RTCM SSR Standard Yes No Licensable Technology Yes No

Table 1. Comparison of high accuracy (sub 10 cm) GNSS differential corrections available over Internet

6/9/2020 Global Differential GPS (GDGPS) System Working Group Actions May 2020 • Data Collection • Operational Construct Options • Current Status of Commercial Market Place Current Point • Common Understanding of GDGPS Capability and Current Uses • Analysis • Determine NASA Baseline Capability Needs • Identify any differences between NASA and National Capability Needs Aug 2020 • Identify Operational Construct for Future Capability Maintenance and Upgrades

Nov 2020 Summary and Advice Questions

• GDGPS is becoming a part of National Infrastructure – should it be? • What is the Current Government user set? • Are there Future uses that should be taken into consideration? • Are there Operating constructs that shouldn’t be missed in the evaluation (funding and oversight)? • Any additional advice or guidance?